Alloy 617 is a major candidate material for use of the intermediate heat exchanger (IHX) of a very high temperature reactor (VHTR) system, which is designed to be used for a 60 year lifetime at a high temperature. Creep crack growth (CCG) behavior as ...
Alloy 617 is a major candidate material for use of the intermediate heat exchanger (IHX) of a very high temperature reactor (VHTR) system, which is designed to be used for a 60 year lifetime at a high temperature. Creep crack growth (CCG) behavior as well as creep deformation, due to creep damage during the long service life at elevated temperatures, is very important. However, the CCG design data to meet the needs of the conceptual designers and/or to develop ASME design code of VHTR system are not available elsewhere. In this study, a series of experimental CCG data was obtained from the CCG tests performed under different applied loads at 800 and 850oC for Alloy 617. The CCG behavior was evaluated in terms of the C<SUP>*</SUP> fracture parameter, and the CCG laws for the two temperatures were proposed and fracture microstructures were observed and discussed.